JPH04306260A - Adhesion accelerator system for one-pack rtv silicone composition - Google Patents

Abstract

PURPOSE: To provide a one-component room-temperature-curable silicone composition which is shelf-stable, scavenger-free and has improved primeless adhesion properties.

CONSTITUTION: There is provided a one-component room-temperature-curable organopolysiloxane composition comprising 100 pts.wt. organopolysiloxane terminated with an alkoxy group and having a viscosity of about 100 to about 1,000,000 cP at 25°C, an effective amount of a diorganotinbisβ-diketonate condensation catalyst, about 0.1 to about 3 pts.wt. cyano-functional polyalkoxysilane, about 0.1 to about 2.0 pts.wt. isocyanato-functional alkoxysilane and about 1 to about 50 pts.wt. polysiloxane plasticizing fluid comprising monoalkylsiloxy units, dialkylsiloxy units and trialkylsiloxy units.

COPYRIGHT: (C)1992,JPO

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-component, scavenger-free, alkoxy-curable, room-temperature-curable silicone rubber composition. In particular, the present invention relates to an adhesion promoting system that improves the primerless adhesion properties of one-part, alkoxy-curable, room temperature curable silicone rubber compositions.

0002

BACKGROUND OF THE INVENTION Adhesion promoters for one-part, alkoxy-curable, room temperature curable (RTV) silicone rubber compositions are well known in the art. For example, Lucas et al., U.S. Pat. Nos. 4,483,973 and 4,528;
No. 353 and Ashby et al., US Pat. No. 4,506,058.

The adhesion-promoting (ie, self-bonding) additives disclosed in the Lucas et al.
Amino, ether, epoxy, isocyanato, cyano,
Silanes functionalized with groups selected from acryloxy and acyloxy.

The adhesion promoting additive disclosed in the Ashby et al. patent is a bis-silylurea compound.

Although the adhesion-promoting compounds disclosed in these Ashby et al. and Lucas et al. patents are effective, they do not provide improved primers for RTV silicone rubber compositions. There continues to be a desire to provide adhesion promoting systems that provide adhesive properties.

The discoveries forming the basis of the present invention are cyano-functional polyalkoxysilanes, isocyanato-functional polyalkoxysilanes, and plasticized polysiloxanes consisting of mono-, dialkyl- and trialkyl-siloxy units. (referred to herein as an "MDT" fluid) provides a synergistic effect on the primerless adhesive properties of one-component, alkoxy-curable RTV silicone rubber compositions. It means showing the effectiveness. The unprimed adhesion properties of RTV silicone rubber compositions containing a cyano-functional polyalkoxysilane, an isocyanato-functional polyalkoxysilane, and an MDT fluid are similar to those without the use of a cyano-functional polyalkoxysilane. containing a combination of isocyanato-functional alkoxysilanes and MDT fluids, or isocyanato-functional alkoxysilanes and MDT without cyano-functional alkoxysilanes.
RTV silicones containing a combination of fluids or a combination of isocyanato-functional and cyano-functional alkoxysilanes without MDT fluids.
The properties are substantially superior to those of other rubber compositions.

Polyalkoxy-terminated polydiorganosiloxane, tin condensation catalyst, adhesion promoter and MD
A one-component RTV composition containing T-fluid may be
U.S. Pat. No. 4,670,532 to Lucas et al.
No. 4,593,085, No. 4,755,578, No. 4,731,411 and No. 4,895,918
Disclosed in the issue. R disclosed in these patents
Both TV compositions are scavenger-containing compositions containing dialkyltin dicarboxylate as a condensation catalyst. These Lucas et al. patents do not disclose or suggest the combination of MDT fluids with cyano- and isocyanato-functional alkoxysilanes.

A polydiorganosiloxane terminated with polyalkoxy, a plasticizer, a dialkyltin-bis-diketonate as a condensation catalyst, and an adhesion promoter [this includes cyanoalkyltrialkoxysilanes and N-trialkoxysilylalkyl selected among amides and imides substituted with scavenger-free one-component RTV compositions are disclosed, for example, in Wengrovius et al., U.S. Pat.
, No. 863,992. The plasticizer fluid disclosed in the Wengrovius et al. patent is not an MDT fluid but a trialkylsilyl-terminated polydiorganosiloxane.

[0009]

OBJECTS OF THE INVENTION It is a principal object of the present invention to provide a shelf-stable, scavenger-free, one-part RTV silicone composition with improved primer-free adhesive properties.

Another object of the present invention is to provide a one-component type R
It is an object of the present invention to provide a method for improving the primer-free adhesive properties of TV silicone compositions.

These and other objects are achieved with the present invention.

0012

SUMMARY OF THE INVENTION The present invention provides a one-component, room temperature curable silicone rubber composition with improved adhesive properties in the absence of a primer. The composition consists of the following ingredients (parts by weight): (A) Polydiorganosiloxane 100 having a viscosity of about 100 to about 1,000,000 centipoise at 25°C.
Department. However, the silicon atom at the end of each polymer chain is terminated with at least two alkoxy groups. The organic group is C(1
-15) is a monovalent hydrocarbon group. (B) An effective amount of a diorganotin bis β-diketonate condensation catalyst having the general formula:

[0013]

embedded image Here, R6 is selected from a C(1-18) monovalent hydrocarbon group and a substituted monovalent hydrocarbon group, and R
7, R8 and R9 are hydrogen, R6, OR6,
The same or different monovalent radicals are selected from the group consisting of -Si(R6)3, -OSi(R6)3, aryl, acyl and nitrile. (C) from about 0.1 to about 3 parts of a cyano-functional polyalkoxysilane having the formula:

[0014]

[Image Omitted] Here, R3 and R4 each independently have 1 carbon atom.
~18 monovalent or substituted hydrocarbon radicals, a ranging from about 0 to about 2, and Z being a saturated, unsaturated, or aromatic, cyano-functional It is a hydrogenated hydrocarbon group. (D) from about 0.1 to about 2.0 parts of an isocyanato-functional alkoxysilane having the formula:

[0015]

[Chemical formula 10] Here, G is R10 group, the following formula

[0016]

R10 is selected from the group of
is a C1-8 monovalent hydrocarbon group or a cyanoalkyl group, R11 is a C1-8 monovalent hydrocarbon group or a cyanoalkyl group, and R12 is an alkylene aryl group.
C2-12 divalent hydrocarbon group selected from ren, alkylene and cycloalkylene and halogenated alkylenearylene, alkylene and cycloalkylene, and b varies from 0 to 3. (E) from about 1 to about 50 parts of a polysiloxane plasticizing fluid comprising the following units:

(i) monoalkylsiloxy units of the formula R13SiO3/2 or siloxy units of the formula SiO4/2 or from 5 to 60 mol % of a mixture of such units, (i
i) 1 to 6 mol % trialkylsiloxy units having the following formula, (R13)3SiO1/2 (iii) 34 to 6 mol% trialkylsiloxy units having the formula
94 mol%.

(R13)2 SiO2/2 where R13 in the formula is a substituted or unsubstituted hydrocarbon group containing about 1 to about 13 carbon atoms. The polysiloxane also has about 0.1 to about 2 silicon-bonded hydroxyl groups.
Contains % by weight. (F) 0 to about 40 parts filler. (G) from about 0 to about 5 parts of a β-diketone having the general formula:

[0019]

embedded image Here, R7, R8 and R9 are as defined above. (H) 0 to about 10 parts polyalkoxysilane crosslinking agent.

[0020]

[Detailed explanation]

Component (A) of the composition of the present invention is characterized in that each end of the polymer chain is terminated by at least two alkoxy groups;
The diorganopolysiloxane polymer has a viscosity ranging from about 100 to about 1,000,000 centipoise at 25°C, preferably from about 5000 to about 200,000 centipoise at 25°C. The organic group of this polymer is C1-1
5 monovalent hydrocarbon group.

The polymer constituting component (A) preferably has the following general formula (I).

[0022]

embedded image Here, R and R2 are each independently a substituted or unsubstituted C(1-15) monovalent hydrocarbon group, and R1
is a C(1-8) aliphatic organic group selected from an alkyl group, an alkyl ether group, an alkyl ester group, an alkyl ketone group, an alkylcyano group, or a C(7-
13), where n is about 50 to about 250
It is an integer in the range up to 0, and b is an integer of 0 or 1.

In formula (I), R is preferably selected from a C(1-13) monovalent hydrocarbon group, a halogenated hydrocarbon group, and a cyanoalkyl group;
is a C(1-8) alkyl group or C(7-13)
is preferably an aralkyl group, and R2 is preferably methyl, phenyl or vinyl. Most preferred are those in which R, R1 and R2 are all methyl.

The terminal silicon atoms of the polymer of component (A) must have at least two alkoxy groups and can have as many as three alkoxy groups according to the above definition.

The polyalkoxy-terminated organopolysiloxane of formula (I) can be prepared in a variety of ways. One method is taught in Cooper et al., U.S. Pat. No. 3,542,901,
Polyalkoxysilane and silano- in the presence of amine catalyst
This method uses a polydiorganosiloxane end-terminated with

Polymers of formula (I) are of Chung
), US Pat. No. 4,515,932 (incorporated by reference). To prepare polymers using the Chung method, silanol-terminated diorganopolysiloxane polymers (organic groups are monovalent ) is reacted with a polyalkoxy crosslinker of the following formula in the presence of an end-coupling catalyst.

[0027]

embedded image However, R1, R2 and “a” are as defined above.

According to the method of Chung, the formula (
Preferably, the silanol-terminated polymer used in preparing the polymer of I) has the following formula:

[0029]

[Chemical formula 15] However, R and "n" are as defined above.

The polymer of formula (I) is
) The terminal coupling reaction formed according to the method of
Alkoxysilanes are end-terminated with silanols in the presence of an end-coupling catalyst selected from the group consisting of Brønsted acids, Lewis acids, stearic acid treated calcium carbonate, and amines, and mixtures thereof. diorganopolysiloxane polymer (one or more types)
It is carried out by mixing with. The catalytic amine can be either a primary, secondary or tertiary amine. The more basic the amine, the better it is as a catalyst. The most preferred catalyst is any of the acids listed above, and most preferred is a combination of one of the acids listed above and an amine. After the end coupling is complete, a silazane (eg, hexamethyldisilazane) is added to deactivate the amine salt catalyst, resulting in a storage-stable polymer. For further information regarding such catalysts and end-coupling reactions, see U.S. Pat. No. 4,515 to Chung.
, No. 932 (incorporated by reference).

Component (B) is a diorganotin-bis-diketonate condensation catalyst of the following general formula (II).

[0032]

embedded image Here, R6 is selected from a C(1-18) monovalent hydrocarbon group and a substituted monovalent hydrocarbon group, and R
7, R8 and R9 are hydrogen, R6, OR6,
The same or different monovalent radicals are selected from the group consisting of -Si(R6)3, -OSi(R6)3, aryl, acyl and nitrile.

Groups included in R6 in formula (II) include, for example, C(6-13) aryl groups and halogenated aryl groups (eg, phenyl, tolyl, chlorophenyl, naphthyl), (1-18) includes aliphatic or cycloaliphatic groups and their halogenated derivatives (e.g. cyclohexyl, cyclobutyl), alkyl groups and alkenyl groups (e.g. methyl, ethyl,
propyl, chloropropyl, butyl, pentyl, hexyl, heptyl, octyl, vinyl, allyl and trifluoropropyl).

Some examples of tin condensation catalysts included in formula (II) include di(n-butyl)tin bis(acetylacetonate), di(n-butyl)tinbis(benzoylacetonate), and di(n-butyl)tinbis(benzoylacetonate). ), di(ethyl)tinbis(
di(methyl)tinbis(pivaloylacetonate), di(n-octyl)tinbis(acetylacetonate), di(n-propyl)tinbis(1,1,1- trifluoroacetylacetonate)
, di(n-butyl)tin bis(ethylacetoacetate), and di(n-butyl)tin(acetylacetonate)
) (ethyl acetoacetate).

A preferred tin catalyst for use in the present invention is di(n-butyl)tin bis(acetylacetonate).

An effective amount of condensation catalyst to promote curing of the RTV composition is, for example, from about 0.01 to about 2.0 parts per 100 parts of alkoxy-functional polydiorganosiloxane (A).
parts by weight, preferably about 0.1 to about 1.0 parts by weight, most preferably about 0.2 to about 0.4 parts by weight.

Component (C) is a cyano-functional polyalkoxysilane having the following general formula (III).

[0038]

[Chemical formula 17] Here, R3 and R4 each independently have 1 carbon atom.
~18 monovalent or substituted hydrocarbon groups, R5 is a C(2-12) divalent hydrocarbon group, and t ranges from about 0 to about 3. It is a number.

In the compound of formula (III), R3 and R4
is an alkyl group (e.g., methyl, ethyl, propyl, etc.), an alkenyl group (e.g., vinyl, allyl, etc.)
, cycloalkyl groups (e.g., cyclohexyl, cycloheptyl, etc.), mononuclear aryl groups (e.g., methyl-phenyl, etc.), and fluoroalkyl groups (e.g., 3,3,3-trifluoropropyl). Can be done. Preferably R3 and R4 are selected from methyl or ethyl, most preferably both are methyl. R5 is preferably an alkylene or arylene-substituted or unsubstituted divalent hydrocarbon group having 2 to 12 carbon atoms, preferably 2 to 8 carbon atoms.

A preferred specific compound falling within the scope of formula (III) above is β-cyanoethyltrimethoxysilane. Other specific compounds include γ-(cyanoethoxy)-3-methylbutenyltrimethoxysilane, 3
-(cyanoethoxy)-3-methylbutenyltrimethoxysilane, β-cyanoethylmethyldimethoxysilane,
β-cyanoethylmethyltrimethoxysilane, 2-cyanoethylmethyldiethoxysilane, 3-cyanopropyltriethoxysilane, cyanopropylmethyldimethoxysilane, 1-cyanoethyltris(methoxyethoxy)
There's silane.

Methods for making compounds within the scope of formula (III) are described, for example, in Lucas et al., US Pat. Nos. 4,483,973 and 4,528,353 (both incorporated by reference). has been disclosed. These compounds are prepared by reacting an olefinic cyanide with trichlorohydridosilane in the presence of a platinum catalyst to form the desired intermediate, followed by alkoxylation of this intermediate to form a cyano-functional alkoxysilane. can be manufactured. Thus, in one particular type of reaction, for example, allyl cyanide and trichlorosilane could be reacted. In this reaction, chlorosilane is reacted with cyanide. Otherwise,
This is because when a methoxylated intermediate is used in a platinum-catalyzed addition reaction, the methoxy group reacts with the cyanide group, reducing the yield of the desired product.

Preferred cyano-functional polyalkoxysilanes for use as component (C) of the compositions of this invention are cyanoalkyltrialkoxysilanes, with cyanoethyltrimethoxysilane being preferred.

Component (C) is present in the compositions of the present invention in an amount of about 0.1 to about 3 parts by weight, preferably about 0.3 to about 1.0 parts by weight, most preferably about 0.3 to about 1.0 parts by weight, based on the total weight of the composition. Preferably about 0.
Present in an amount ranging from 3 to about 0.7 parts by weight.

Component (D) is an adhesion promoter consisting of an isocyanato-functional alkoxysilane having the following formula (IV).

[0045]

[Chemical formula 18] Here, G is an R10 group, a group of the following formula,

[0046]

embedded image R10 is selected from styryl group, vinyl group, allyl group, chloroallyl group, and cyclohexenyl group, and R10 is C
1-8 monovalent hydrocarbon group or cyanoalkyl group, R11 is a C1-8 monovalent hydrocarbon group or cyanoalkyl group, R12 is alkylenearylene, alkylene and cycloalkylene, and halogen alkylene is a C2-12 divalent hydrocarbon group selected from arylene, alkylene and cycloalkylene, and b varies from 0 to 3.

For further information regarding such compounds, see Beers, US Pat.
No. 00,129, Berger U.S. Pat. No. 3,821,218, and Luc
U.S. Pat. Nos. 4,483,973 and 4 to as) et al.
, 528,353 (incorporated by reference).

The most preferred adhesion promoters included in formula (IV) are 1,3,5-tristrimethoxysilylpropylisocyanate and bis-1,3-trimethoxysilylpropylisocyanurate. To prepare such compounds, the corresponding alkoxyhydridosilanes are used and reacted with unsaturated isocyanurates or cyanurates in the presence of a platinum catalyst. A hydride group then attaches to an unsaturated group such as an allyl group on the isocyanurate nucleus. The group R12 can be selected from any hydrocarbon group, saturated or unsaturated, as long as it does not affect the adhesion promoting activity of the compound. It is noted that less complex compounds are undesirable because they are relatively difficult to prepare and obtain, and therefore more expensive. Other specific compounds falling within the scope of formula (IV) above are:
1,3,5-tristrimethoxysilylpropylisocyanurate, 1,3,5-tristrimethoxysilylethylisocyanurate, 1,3,5-trismethyldimethoxysilylpropylisocyanurate, 1, 3,5-
Trismethyldiethoxysilylpropyl isocyanurate
It is.

The isocyanato-functional alkoxysilane adhesion promoter is typically present in the RTV compositions of the present invention in an amount of from about 0.1 to about 2.0 parts by weight per 100 parts of the alkoxy-functional polydiorganosiloxane (A). , preferably about 0.
2 to about 1.0 parts by weight, most preferably about 0.3 to about 0.0 parts by weight.
Present in an amount within the range of 7 parts by weight.

Component (E) is a polysiloxane plasticizing fluid containing the following units: (i) a monoalkylsiloxy unit having the following formula (V), (V)
R13SiO3/2 or a siloxy unit of the following formula (VI), (VI)
SiO4/2 or from 5 to 60 mol% of a mixture of such units, (ii) from 1 to 6 mol% of trialkylsiloxy units having the following formula (VII), (VII) (R
13) 3 SiO1/2 (iii) The following formula (VIII)
34 to 94 mol% of dialkylsiloxy units having.

(VIII) (
R13)2 SiO2/2 However, R13 in the above formula
is a substituted or unsubstituted hydrocarbon group containing about 1 to about 13 carbon atoms. The polysiloxane also contains from about 0.1 to about 2 weight percent silicon-bonded hydroxyl groups.

In the above formulas (V) to (VIII), R13 is preferably methyl.

The polysiloxane fluid (MDT fluid) contains about 1 to about 50 parts, preferably about 5 to about 40 parts, and most preferably about 10 parts per 100 parts of polyalkoxy-terminated polydiorganosiloxane (A). present in the compositions of the present invention in an amount ranging from about 30 parts.

MDT fluids can be made by simultaneously hydrolyzing a blend of methyl mono-, di-, and trichlorosilanes in a sequential hydrolysis process.

The RTV composition of the present invention further comprises component (F)
It is preferable to also include a filler as a filler. Compositions of the invention include, for example, titanium dioxide, zirconium silicate, silica aerogel, iron oxide, diatomaceous earth, fumed silica, carbon black, precipitated silica, glass fibers, polyvinyl chloride, ground quartz, carbonate. Various fillers such as calcium can be incorporated. Preferred fillers for use in the compositions of the invention are reinforcing fillers, with fumed silica fillers being most preferred.

The amount of filler used can vary within wide limits depending on the intended use. For example, for certain sealant applications, the curable compositions of the present invention can be used without fillers. In addition, in applications where the composition of the present invention is used in the production of binders, alkoxy-terminated polydiorganosiloxanes (
As much as 700 parts or more of filler per 100 parts by weight of A) can be used.

The compositions of the present invention can also be used as construction sealants and caulking compounds. The exact amount of filler used will therefore depend on such factors as the intended use of the composition and the type of filler used. Organopolysiloxane (A) 1
from about 5 to about 300 parts filler per 00 parts (which is about 4
up to 0 parts, preferably from about 5 to about 40 parts of reinforcing filler;
(e.g., can contain fumed silica fillers)
It is preferable to use

It is often advantageous to pre-treat the silica filler with an activator such as octamethylcyclotetrasiloxane.

[0059] A preferred embodiment of the RTV composition of the present invention comprises:
Furthermore, a β-diketone [component (G)] that can form a chelate compound with the tin condensation catalyst of formula (II)
Also contains. The β-diketones [hereinafter referred to as "chelating ligands"] have been found to impart improved storage stability to RTV compositions when used in effective amounts. Chelating ligands useful in the present invention have the following general formula (IX).

[0060]

embedded image Here, R7, R8 and R9 are as defined above.

A preferred chelate-forming ligand from the standpoint of cost and availability is 2,4-pentanedione. However, the U.S. Environmental Protection Agency (Environmenta
l Protection Agency) recently 2,
Regarding 4-pentanedione, the “Regulations for Significant New Uses (Si
gnificant New Use Rule)” (
SNUR) was issued. It states that 2,4-pentanedione can be a neurotoxin, mutagen, and growth-suppressing toxin when inhaled. This SNUR
essentially prohibits the use of 2,4-pentanedione in new products, thus significantly limiting the marketability of RTV sealants containing 2,4-pentanedione. Other less toxic β-ketones can be used in place of 2,4-pentanedione. For example,
2,2,6,6-tetramethyl-3,5-heptanedione, 1,1,1-trifluoro-2,4-pentanedione, 1-phenyl-1,3-butanedione, 2,4-hexanedione , and 5,7-nonanedione. The most preferred of these non-toxic β-diketones is 2,4-hexanedione.

[0062] The chelating ligand is the RT of the present invention.
V composition, about 0 to about 5 parts by weight, preferably about 0.2 to about 0.8 parts by weight, most preferably about 0.5 parts by weight, per 100 parts of alkoxy-functional polydiorganosiloxane (A).
It can be present in an amount ranging from 3 to about 0.5 parts by weight.

The RTV composition of the present invention further comprises a polyalkoxysilane crosslinking agent [component (H)] of the following general formula (X).
may contain.

[0064]

embedded image Here, R1, R2 and b are as defined above.

Typical compounds represented by formula (X) include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, tetraethoxysilane, and vinyltrimethoxysilane. Methyltrimethoxysilane is preferred.

[0066] This polyalkoxy crosslinking agent is the RT of the present invention.
V composition, typically from about 0 to about 20 parts per 100 parts of alkoxy-functional polydiorganosiloxane of formula (I).
It is present in an amount within the range of parts by weight, preferably from about 0.1 to about 2 parts by weight, and most preferably from about 0.5 to about 1.0 parts by weight.

[0067] The composition of the present invention further has a temperature of 10 to
Triorganosilyl-terminated diorganopolysiloxane (I) with a viscosity of 5000 centipoise
) may be contained in an amount of about 1 to about 50 parts by weight. The organic group in this case is a monovalent hydrocarbon group containing 1 to 8 carbon atoms.
Preferably, it contains Such linear diorganopolysiloxane polymers are useful as plasticizers. Such plasticizers are preferably free of silanol groups, but typically up to about 500 ppm of silanol groups are present. Further, the organo substituent is preferably methyl, and the viscosity is preferably in the range of 10 to 1000 centipoise at 25°C.

Other compounds, such as flame retardants such as platinum, may also be incorporated into the compositions of the invention.

The RTV compositions of the present invention can be prepared by methods known in the art. For example, all components may be mixed together at the same time. In a preferred method, a mixture of polyalkoxy-terminated polymer, cyano-functional polyalkoxysilane, and filler is vigorously blended, followed by crosslinking agents, tin catalysts, stabilizers/scavengers, adhesion promoters, and other ingredients. (eg, plasticizers) are added individually or together and then thoroughly mixed under anhydrous conditions.

The RTV composition of the present invention can be applied to a variety of substrates, particularly masonry substrates. Examples of suitable substrates include aluminum, glass, polyacrylate, polycarbonate, polyvinyl chloride and concrete.

[0071]

DESCRIPTION OF THE EXAMPLES The following examples are included for the purpose of illustrating the invention. These examples are not included for the purpose of defining the scope or boundaries of the invention. In the Examples, all parts are by weight.

Experimental Example 1 A polydimethylsilicone polymer terminated with methyldimethoxysilyl was prepared as follows. The following materials were mixed. 100 parts of a hydroxy-terminated polydimethylsilicone polymer having a viscosity of 110,000 centipoise at 25°C. 2.0 parts of methyltrimethoxysilane. 0.60 parts of diisobutylamine. 0.20 parts of formic acid.

The mixture was heated under a nitrogen atmosphere for 3.0 hours at 110
heated to ℃. SiFTNMR analysis shows that the silicone polymer is now CH3(CH3O)2S
It was found that the end was capped by the i-group. The viscosity of the polymer after end-capping is 25°C.
It was 130,000 centipoise.

Examples 2-6 below demonstrate the use of cyano-functional polyalkoxysilane adhesion promoters and isocyanato-functional polyalkoxysilane adhesion promoters in combination and the use of each of these adhesion promoters alone. The effects of the one-component RTV silicone compositions on primerless (ie, peel) adhesion properties are compared. Furthermore, in Examples 2 and 7, RT
The effect on peel adhesion when MDT oil is omitted from the V composition is shown.

Regarding the compositions produced in Examples 2 to 6,
WPSTM primerless peel adhesion to aluminum, glass, polyacrylate, polycarbonate, polyvinyl chloride and concrete
Tested by C-128. At this time, the RTV compositions were tested by being cured for 14 days at 72° C. and 50% relative humidity, and by being soaked in water for 7 days after being cured for 14 days. The results are shown in Table 1. Example 2 In Example 2, a 30 mm Warner-Plyder (
Figure 2 illustrates the continuous production of the composition of the invention using a Werner-Pfleiderer twin-screw extruder.

To barrel 1 of this extruder were continuously added 16 parts of fumed silica which had been previously treated with octamethylcyclotetrasiloxane (D4). 1.50 parts of cyanoethyltrimethoxysilane was also continuously added to this barrel 1. 30 parts silicone plasticizing fluid terminated with (CH3)3SiO and 1 part MDT oil having a viscosity of 100 centipoise at 25°C.
0 parts were added continuously to barrel 8 of the extruder. Barrel 12 contains 1.1 parts of 1,3,5-tris(3-trimethoxysilylpropyl) isocyanurate and 0.45 parts of dibutyltin-bis-acetylacetonate curing catalyst.
part, 2,4-pentanedione chelate-forming ligand 0
．． 45 parts and 1.50 parts of methyltrimethoxysilane were added. Werner-P
fleiderer) twin-screw extruder is 75℃
It was kept at a temperature of Air was removed by vacuum through the barrel 11 of the extruder. RTV sealant was produced at a rate of 30 pounds/hour. Example 3 The procedure described in Example 2 was repeated except that cyanoethyltrimethoxysilane was omitted. In Example 3, 1
,3,5-tris(3-trimethoxysilylpropyl)
Isocyanurate (1.1 parts) was the only adhesion promoter. Example 4 The procedure described in Example 2 was repeated except that 1,3,5-tris(3-trimethoxysilylpropyl)isocyanurate was omitted. In Example 4, cyanoethyltrimethoxysilane (1.50 parts) was the only adhesion promoter. Example 5 The procedure described in Example 2 was repeated except that cyanoethyltrimethoxysilane was omitted. In Example 5, 1
,3,5-tris(3-trimethoxysilylpropyl)
Isocyanurate (2.2 parts) was the only adhesion promoter. Example 6 The procedure described in Example 2 was repeated except that 1,3,5-tris(3-trimethoxysilylpropyl)isocyanurate was omitted. In Example 6, cyanoethyltrimethoxysilane (2.2 parts) was the only adhesion promoter.

In Table 1 below, (AMB) is 72°C, 50°C.
14 days cure at % relative humidity, (WET) is 7
Cure for 14 days at 2° C. and 50% relative humidity followed by 7 days in water. "ANOD. ALUM."
"PVC" refers to polyvinyl chloride. "PPI" means pounds per inch and "%COH.FAIL" means % cohesive failure.

[0078]

Table 1 As the data listed in Table 1 show, the use of both cyano- and isocyanato-functional polyalkoxysilane adhesion promoters results in a cyano-functional R containing either a polyalkoxysilane adhesion promoter or an isocyanato-functional polyalkoxysilane adhesion promoter as the sole adhesion promoter.
An RTV silicone composition is obtained which has improved primerless adhesive properties compared to TV compositions. Example 7 Example 2 was repeated. However, "M" having a viscosity of 100 centipoise at 25°C [i.e. (CH3
30 parts of polydimethylsilicone fluid terminated with )3SiO1/2] and no MDT fluid were used. Table 2 shows the peel adhesion test results.

[0079]

[Table 2]

Claims (11)

[Claims] Claim 1: (A) about 100 to about 1,000 at 25°C
100 parts by weight of a polydiorganosiloxane having a viscosity of 0,000 centipoise (with the proviso that the silicon atoms at the ends of each polymer chain are terminated with at least two alkoxy groups) and (B) the general formula [ where R6 is selected from C(1-18) monovalent hydrocarbon groups and substituted monovalent hydrocarbon groups;
7, R8 and R9 are hydrogen, R6, OR6,
-Si(R6)3, -OSi(R6)3, the same or different monovalent groups selected from the group consisting of aryl, acyl and nitrile]. - an effective amount of the condensation catalyst;
(C) Formula 2 [wherein R3 and R4 are each independently a monovalent hydrocarbon group or a substituted hydrocarbon group having 1 to about 18 carbon atoms, and a is about 0 from about 0.1 to about 3 parts by weight of a cyano-functional polyalkoxysilane having a number ranging from about 2 to about 2, and Z is a saturated, unsaturated or aromatic cyano-functionalized hydrocarbon group. And, formula (D) [
[Formula 3] [wherein G is selected from R10 group, a group of the formula [Image Omitted], a styryl group, a vinyl group, an allyl group, a chloroallyl group and a cyclohexenyl group, and R10
is a C1-8 monovalent hydrocarbon group or a cyanoalkyl group, R11 is a C1-8 monovalent hydrocarbon group or a cyanoalkyl group, and R12 is an alkylene aryl group.
a C2-12 divalent hydrocarbon group selected from ren, alkylene and cycloalkylene and halogenated alkylenearylene, alkylene and cycloalkylene, b varying from 0 to 3]; The isocyanato-functional alkoxysilane with about 0.1
~2.0 parts by weight and (E)(i) monoalkylsiloxy units having the formula R13SiO3/2 or formula SiO
4/2 siloxy units or mixtures of such units 5-6
(ii) 1 to 6 mol% of trialkylsiloxy units having the formula (R13)3SiO1/2;
iii) from about 1 to about 50 parts by weight of a polysiloxane plasticizing fluid comprising 34 to 94 mole % of dialkylsiloxy units having the formula (R13)2 SiO2/2, where R13 represents about 1 to about 50 parts by weight of dialkylsiloxy units; 13 substituted or unsubstituted hydrocarbon groups, and this polysiloxane contains about 0.1 silicon-bonded hydroxyl groups.
~2% by weight] and (F) filler 0~4% by weight.
0 parts by weight, (G) about 0 to about 5 parts by weight of a β-diketone having the general formula: wherein R7, R8 and R9 are as previously defined; and (H) polyalkoxy A one-part room temperature curable silicone composition with improved primerless adhesive properties comprising 0 to about 10 parts by weight of a silane crosslinker. 2. The polydiorganosiloxane has the general formula [Image Omitted] [wherein R and R2 are each independently a substituted or unsubstituted C(1-15) monovalent hydrocarbon group, R1
is a C(1-8) aliphatic organic group or C(7-
13), where n is about 50 to about 250
b is an integer ranging from 0 to 0, and b is an integer of 0 or 1. 3. The room temperature curable composition of claim 1, wherein R13 is methyl. 4. The room temperature curable composition according to claim 1, wherein the condensation catalyst is di(n-butyl)tin bis(acetylacetonate). 5. The room temperature curable composition of claim 1, wherein the cyano-functional polyalkoxysilane is β-cyanoethyltrimethoxysilane. 6. The isocyanato-functional polyalkoxysilane is 1,3,5-tristrimethoxysilylpropylisocyanate or bis-1,3-trimethoxysilylpropylisocyanurate. The room temperature curable composition described. 7. The room temperature curable composition of claim 1, wherein the polyalkoxysilane crosslinking agent is methyltrimethoxysilane. 8. The room temperature curable composition according to claim 1, wherein the filler is a reinforcing filler. 9. The room temperature curable composition of claim 1, wherein the β-diketone is present in an amount ranging from about 0.2 to about 0.8 parts. 10. The cyano-functional polyalkoxysilane is present in an amount ranging from about 0.3 to about 1 part by weight, and the isocyanato-functional polyalkoxysilane is present in an amount ranging from about 0.2 to about 1 part by weight.
2. The room temperature curable composition of claim 1, wherein the room temperature curable composition is present in an amount ranging from parts by weight. 11. (A) Formula 7 [wherein R, R1 and R2 are each a methyl group, n is an integer ranging from about 50 to about 2500,
b is an integer of 0 or 1]; (B) about 0.2 to about 0.4 parts by weight of di(n-butyl)tin bis(acetylacetonate); (C) about 0.3 to about 0.7 parts by weight of β-cyanoethyltrimethoxysilane; and (D) about 0.3 to about 1,3,5-tristrimethoxysilylpropyl isocyanate.
about 0.7 parts by weight and (E)(i) monoalkylsiloxy units having the formula R13SiO3/2 or the formula SiO
4/2 siloxy units or mixtures of such units 5-6
(ii) 1 to 6 mol% of trialkylsiloxy units having the formula (R13)3SiO1/2;
iii) about 10 to about 30 parts by weight of a polysiloxane plasticizing fluid consisting of 34 to 94 mol % of dialkylsiloxy units having the formula (R13)2 SiO2/2 [wherein R13 is a methyl group; Siloxane has a silicon-bonded hydroxyl group of about 0.1
(F) about 5 to about 40 parts by weight of fumed silica filler; and (G) about 0.3 to about 0.5 parts by weight of 2,4-hexanedione. , (H) about 0.5 to about 1.0 parts by weight of methyltrimethoxysilane,
A storage-stable, one-component, room-temperature-curing silicone composition with improved primer-free adhesive properties.